RE: [Chrysler300] FYI swapping master cyl locations

300C thru '59s I believe ALL HAD 2/TWO FACTORY potential height locations to mount their master cylinders - this to allow for if 'power brake' or 'non power brakes'.
,
And I not sure what change supposed happened at dates just given in emails, as I had a 300C/300D (1958) bellows type brake booster that I just bolted up to a (factory) non power brake 1959 Dodge Coronet.

It is correct there is a different pedal arm location where the power brake booster pushrod comes off the pedal versus non power brakes.
So that means if swapping from power to non power brake system, or vice versa, one must also use/change the vertical steel plate that holds the power booster to the firewall.
And/but on my'57s - 59s, the firewall is drilled with exact same position (lower) 6 holes that allow the master cylinder be bolted up, whether it be the higher position for non power brakes, or the lower (master cylinder bolt up) position for power brakes.

And obviously, the power brake uses a rocker type pedal assembly that is totally different to the 'non power' one piece simple brake pedal. And the other thing to note/know - the pedal box assembly that pedals swing from are different - power brake one uses a vertical spring close to firewall to keep the rocker pedal part loaded, and non power assembly does not have needed tag for spring.

Sounds complicated - but basically if one uses all parts from each system, it bolts up, but it a mongrel to unbolt and rebolt the pedal hanger assembly/bracket, as it fits into back/upper part of dash around the steering column. It is this bracket that has the 6 threaded studs that go thru the firewall, and 4 of these then hold the master cylinder, depending on whichever height matches lower 4 studs.
BUT YOU SHOULD NOT SWAP SINGLE PARTS OF THE TWO DIFFERENT SYSTEMS - IT MUST BE ALL OR NONE. However the master cylinder is bodywise pretty much the same, although pushrod fixing will need be swapped I think

The power boosters are factory dated on their face plate in the case of bellows type, so that helps id what year one of them you have,

Christopher in Australia

To: ronbo97@xxxxxxxxxxx; Chrysler300@xxxxxxxxxxxxxxx
From: Chrysler300-noreply@xxxxxxxxxxxxxxx
Date: Tue, 31 Mar 2015 17:28:07 -0400
Subject: RE: [Chrysler300] FYI After market brake cyl issues

I thought same way. Why would they do that? But compared firewall drilling and mount plates..different on the car I had. Beyond that I do not know. Had to fabricate pedal arm hole and push rod mount, going manual where power was, 1960. Put together stock took 500lbs to stop car ,manual. With smallest bore (manual) master. Works fine now, drove it to Ct meet.

Call it something to be aware of…

From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of 'Ron Waters' ronbo97@xxxxxxxxxxx [Chrysler300]
Sent: Tuesday, March 31, 2015 1:06 PM
To: Chrysler300@xxxxxxxxxxxxxxx
Subject: Re: [Chrysler300] FYI After market brake cyl issues

Changeover for two-platform to three-platform brakes happened in Dec 1958/Jan 1959. I have a ton of factory documentation to support that.

Worth reading:

http://imperialclub.com/Repair/Lit/Master/138/index.htm

Also worth buying is a 1959 and 1960 factory parts book.

All bodies were set up to accomodate both power and non-power brakes. Otherwise, it would be a logistical and production nightmare. When changing over from one to another, as I have done, it's imperative that you get the correct pedal assembly, master cylinder, vacuum port for the intake, etc.

Ron

----- Original Message -----
From: 'John Grady' jkg@xxxxxxxxxxxxxxxxx [Chrysler300]
To: 'David Schwandt' ; 'chrysler300@xxxxxxxxxxxxxxx Club'
Sent: Tuesday, March 31, 2015 12:28 PM
Subject: RE: [Chrysler300] FYI After market brake cyl issues

I am not sure that info in link is right, re : when it happened—not 59?? ….our experience is that this change happened in mid 58? On 300D, along with larger control arm bushings , other stuff. Protecting torsion bars from snapping off. Late 58-61 are the same; 57 early 58 the same . I do not know this as hard cold facts , but we have had this issue ;58D can have either size, often you get the wrong ones. Documentation of all this generally a wreck at auto parts stores. This link says 59 was change …??? .or maybe only low production hi perf like 300 got it in 58? . But upgrading to 60 stuff (or 61) with the 60-61 backing plates you get a much better , more evolved setup. 59 MIGHT be same. The big flat spring (easy to put that in wrong, too) is thicker , cams stay put, backing plate spacing front to back therefore thicker . Other issue is that the large diameter 12” 60-61 backing plates described are rare compared to those improved backing plates for dodge plymouth, lower power, or short wheelbase Chryslers. Smaller diameter drums, different width shoes too. Buyer beware ; I bought a whole set up, all wrong. I believe shoes are different too, some have that little depressed area to hook return spring, --I forget the exact issues.

Steering box changes too…/When? Later ones , late 58/59 on up seem to be used for quite a few years after, in many car lines ; anyone know?

I do agree a lot of bad press on total contact brakes has come from well meaning people mixing up all these pieces .

Power brake masters vs non power are another quagmire..the pedal ratios are different, not just the masters,-- master mounts,(that plate)_ firewall drillings and pedal push rod location, vs MC bore height . Parts physically fit that do not work in that area. The firewall differences are really surprising, car body must have been designated power brakes or not from get go, sets pedal ratio. . Which also sets pedal swing arm heights in upper dash and ratios on pedal arm drillings(all this on 1960 Matador—same body as F) ..and adding to confusion there are often two drillings on pedal arm , both wrong for manual brakes. At least two pedal arms. Plus bores of cylinders.

Maybe others more fanatic on the record keeping side can chime in.. Or maybe all this exists somewhere..

Yes ----save all OEM stuff off these cars….

Why getting an unmolested car matters, too.

From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of 'David Schwandt' finsruskw@xxxxxxxxxxxxxxx [Chrysler300]
Sent: Monday, March 30, 2015 8:07 AM
To: chrysler300@xxxxxxxxxxxxxxx Club
Subject: [Chrysler300] FYI After market brake cyl issues

FYI
Good thread w/pic’s about Chinese re-pop junk brake cyl’s
Makes me think I should start saving the old OEM cyls for cores.

http://www.forwardlook.net/forums/forums/thread-view.asp?tid=57103&posts=4#M473840

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Posted by: christopher <thelastbestgenius@xxxxxxxxxxx>

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RE: [Chrysler300] FYI swapping master cyl locations - brake cyl issues